Butterfly Islands: April 2021

Friday, 23 April 2021

A Promise of Spring on our Coastal Cliffs.

A walk along a very breezy clifftop today allowed me to access a section of the landslip close to Compton Bay. The coastline all along the south west of the Isle of Wight suffers from coastal slump as the cliffs periodically slide towards the sea. In fact evidence of recent slippages are for all to see along the path taken today.

It seems that only Small Copper butterflies were on show in this area of landslip this afternoon as I recorded at least six individuals. They were particularly fond of the odd clump of thrift, as just a few early flowers were to be seen dotted around. All too soon the cliffs will be covered in their bright pink blooms which are a favourite of the Glanville Fritillary which is due to make an imminent appearance.

Sunday, 18 April 2021

Another Spring Species.

Now that we are enjoying a period of settled sunny weather following the cold of early April, spring is now catching up with the new emerging butterfly species. Green Hairstreak numbers have today increased to three at the site I have visited during the last few days and now at least two Grizzled Skippers are present.

Thursday, 15 April 2021

Back for Another Look.

There was no increase in butterfly numbers when I returned to the site visited yesterday. Just one Green Hairstreak and a Small Copper. Green Hairstreak should become more numerous during the next week and we can look forward to other spring species appearing at this location.

Wednesday, 14 April 2021

A First Sight of the Spring Emergents.

The warm weather of early April gave way to a very cold north to north-east wind resulting in low temperatures for the last week or so and consequently hardly any butterfly activity. However with some sunshine and lighter winds today I was pleased to see two spring emergent species in the West Wight. A first Green Hairstreak of the season and likewise a Small Copper. Both enjoying the warm sunshine in the sheltered spot they had chosen.

Thursday, 1 April 2021

A Walk in the Woods.

Although not as warm as the last few days, it was nevertheless a lovely early spring day and the butterflies responded to the sunshine at Bouldnor. I was disappointed not to see any new emergent butterflies but the hibernators were on show with numerous sightings of Peacock, five Comma, three Red Admiral, and two male Brimstone. One of the latter spent some time flitting from flower to flower enjoying the many primrose plants along the track.

The Adonis Blue

The Large Tortoiseshell

It seems the general view on the status of the Large Tortoiseshell in Britain is that it is now extinct as a breeding butterfly.
It is a butterfly of woodland edges and hedgerows that abound in willows,elms,and poplars.These trees are used by the adult to lay its eggs and this single brood appears in July and August.The emerging butterfly then hibernates over the winter in log piles and hollow trees until the next spring.
On the Isle of Wight sightings are more often than not made from early March to April.Have these butterflies overwintered on the Island or have they come from the continent where it is common?
Any sightings made in July/August pose the same question.Another explanation could be that captive-bred releases are responsible.Only the discovery of eggs and caterpillars will probably answer these questions.

I can now report that evidence has been found of breeding just along the coast at Portland in Dorset (June 2020) and again at the same location in the summer of 2021.

The Glanville Fritillary

This elegant butterfly is mainly confined to the crumbling undercliffs and chalk downs of the Isle of Wight.It is also found on the Channel Islands and at one or two isolated colonies on the British mainland.In Britain the Glanville Fritillary is at the extreme north-western edge of its range.On the continent it is readily found in flowery habitats.
Around the southern shores of the Isle of Wight the cliffs constantly erode causing them to slip away and provide perfect conditions for new growths of the butterflies laval host plant,Ribwort Plantain.
The eggs are laid to the underside of the leaves of this plant and normally hatch after about three weeks.The resulting caterpillars live together in communal webs spun over the plantain.In the autumn they hibernate and recommence feeding in the spring,eventually dispersing to prepare for pupation.
The adult butterfly is on the wing from May to the end of June with the female being larger than the male.They will feed on,amongst other things, Birds-foot Trefoil and Thrift.

The Wall Brown

On the Isle of Wight in particular,the Wall Brown is a butterfly of field edges,coastal cliffs and dunes,and rabbit-grazed downland.
The male is territorial and spends much of the time patrolling and basking on the ground.
The female,which lacks the males conspicuous dark sex brand across the forewings,is larger.The undersides of both sexes are beautifully cryptic when at rest.
The Wall Brown generally produces two broods a year,the first from late April until late June and the second from mid-July to mid-September.